diff options
Diffstat (limited to 'drivers/pci/hotplug/pciehp_hpc.c')
| -rw-r--r-- | drivers/pci/hotplug/pciehp_hpc.c | 1092 |
1 files changed, 1092 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c new file mode 100644 index 000000000..358f07728 --- /dev/null +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -0,0 +1,1092 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PCI Express PCI Hot Plug Driver + * + * Copyright (C) 1995,2001 Compaq Computer Corporation + * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) + * Copyright (C) 2001 IBM Corp. + * Copyright (C) 2003-2004 Intel Corporation + * + * All rights reserved. + * + * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com> + */ + +#define dev_fmt(fmt) "pciehp: " fmt + +#include <linux/dmi.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/jiffies.h> +#include <linux/kthread.h> +#include <linux/pci.h> +#include <linux/pm_runtime.h> +#include <linux/interrupt.h> +#include <linux/slab.h> + +#include "../pci.h" +#include "pciehp.h" + +static const struct dmi_system_id inband_presence_disabled_dmi_table[] = { + /* + * Match all Dell systems, as some Dell systems have inband + * presence disabled on NVMe slots (but don't support the bit to + * report it). Setting inband presence disabled should have no + * negative effect, except on broken hotplug slots that never + * assert presence detect--and those will still work, they will + * just have a bit of extra delay before being probed. + */ + { + .ident = "Dell System", + .matches = { + DMI_MATCH(DMI_OEM_STRING, "Dell System"), + }, + }, + {} +}; + +static inline struct pci_dev *ctrl_dev(struct controller *ctrl) +{ + return ctrl->pcie->port; +} + +static irqreturn_t pciehp_isr(int irq, void *dev_id); +static irqreturn_t pciehp_ist(int irq, void *dev_id); +static int pciehp_poll(void *data); + +static inline int pciehp_request_irq(struct controller *ctrl) +{ + int retval, irq = ctrl->pcie->irq; + + if (pciehp_poll_mode) { + ctrl->poll_thread = kthread_run(&pciehp_poll, ctrl, + "pciehp_poll-%s", + slot_name(ctrl)); + return PTR_ERR_OR_ZERO(ctrl->poll_thread); + } + + /* Installs the interrupt handler */ + retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist, + IRQF_SHARED, "pciehp", ctrl); + if (retval) + ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n", + irq); + return retval; +} + +static inline void pciehp_free_irq(struct controller *ctrl) +{ + if (pciehp_poll_mode) + kthread_stop(ctrl->poll_thread); + else + free_irq(ctrl->pcie->irq, ctrl); +} + +static int pcie_poll_cmd(struct controller *ctrl, int timeout) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_status; + + do { + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (PCI_POSSIBLE_ERROR(slot_status)) { + ctrl_info(ctrl, "%s: no response from device\n", + __func__); + return 0; + } + + if (slot_status & PCI_EXP_SLTSTA_CC) { + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_CC); + ctrl->cmd_busy = 0; + smp_mb(); + return 1; + } + msleep(10); + timeout -= 10; + } while (timeout >= 0); + return 0; /* timeout */ +} + +static void pcie_wait_cmd(struct controller *ctrl) +{ + unsigned int msecs = pciehp_poll_mode ? 2500 : 1000; + unsigned long duration = msecs_to_jiffies(msecs); + unsigned long cmd_timeout = ctrl->cmd_started + duration; + unsigned long now, timeout; + int rc; + + /* + * If the controller does not generate notifications for command + * completions, we never need to wait between writes. + */ + if (NO_CMD_CMPL(ctrl)) + return; + + if (!ctrl->cmd_busy) + return; + + /* + * Even if the command has already timed out, we want to call + * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC. + */ + now = jiffies; + if (time_before_eq(cmd_timeout, now)) + timeout = 1; + else + timeout = cmd_timeout - now; + + if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE && + ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE) + rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout); + else + rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout)); + + if (!rc) + ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n", + ctrl->slot_ctrl, + jiffies_to_msecs(jiffies - ctrl->cmd_started)); +} + +#define CC_ERRATUM_MASK (PCI_EXP_SLTCTL_PCC | \ + PCI_EXP_SLTCTL_PIC | \ + PCI_EXP_SLTCTL_AIC | \ + PCI_EXP_SLTCTL_EIC) + +static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd, + u16 mask, bool wait) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_ctrl_orig, slot_ctrl; + + mutex_lock(&ctrl->ctrl_lock); + + /* + * Always wait for any previous command that might still be in progress + */ + pcie_wait_cmd(ctrl); + + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + if (PCI_POSSIBLE_ERROR(slot_ctrl)) { + ctrl_info(ctrl, "%s: no response from device\n", __func__); + goto out; + } + + slot_ctrl_orig = slot_ctrl; + slot_ctrl &= ~mask; + slot_ctrl |= (cmd & mask); + ctrl->cmd_busy = 1; + smp_mb(); + ctrl->slot_ctrl = slot_ctrl; + pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl); + ctrl->cmd_started = jiffies; + + /* + * Controllers with the Intel CF118 and similar errata advertise + * Command Completed support, but they only set Command Completed + * if we change the "Control" bits for power, power indicator, + * attention indicator, or interlock. If we only change the + * "Enable" bits, they never set the Command Completed bit. + */ + if (pdev->broken_cmd_compl && + (slot_ctrl_orig & CC_ERRATUM_MASK) == (slot_ctrl & CC_ERRATUM_MASK)) + ctrl->cmd_busy = 0; + + /* + * Optionally wait for the hardware to be ready for a new command, + * indicating completion of the above issued command. + */ + if (wait) + pcie_wait_cmd(ctrl); + +out: + mutex_unlock(&ctrl->ctrl_lock); +} + +/** + * pcie_write_cmd - Issue controller command + * @ctrl: controller to which the command is issued + * @cmd: command value written to slot control register + * @mask: bitmask of slot control register to be modified + */ +static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) +{ + pcie_do_write_cmd(ctrl, cmd, mask, true); +} + +/* Same as above without waiting for the hardware to latch */ +static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask) +{ + pcie_do_write_cmd(ctrl, cmd, mask, false); +} + +/** + * pciehp_check_link_active() - Is the link active + * @ctrl: PCIe hotplug controller + * + * Check whether the downstream link is currently active. Note it is + * possible that the card is removed immediately after this so the + * caller may need to take it into account. + * + * If the hotplug controller itself is not available anymore returns + * %-ENODEV. + */ +int pciehp_check_link_active(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 lnk_status; + int ret; + + ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status)) + return -ENODEV; + + ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); + ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status); + + return ret; +} + +static bool pci_bus_check_dev(struct pci_bus *bus, int devfn) +{ + u32 l; + int count = 0; + int delay = 1000, step = 20; + bool found = false; + + do { + found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0); + count++; + + if (found) + break; + + msleep(step); + delay -= step; + } while (delay > 0); + + if (count > 1) + pr_debug("pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n", + pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), + PCI_FUNC(devfn), count, step, l); + + return found; +} + +static void pcie_wait_for_presence(struct pci_dev *pdev) +{ + int timeout = 1250; + u16 slot_status; + + do { + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (slot_status & PCI_EXP_SLTSTA_PDS) + return; + msleep(10); + timeout -= 10; + } while (timeout > 0); +} + +int pciehp_check_link_status(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + bool found; + u16 lnk_status; + + if (!pcie_wait_for_link(pdev, true)) { + ctrl_info(ctrl, "Slot(%s): No link\n", slot_name(ctrl)); + return -1; + } + + if (ctrl->inband_presence_disabled) + pcie_wait_for_presence(pdev); + + found = pci_bus_check_dev(ctrl->pcie->port->subordinate, + PCI_DEVFN(0, 0)); + + /* ignore link or presence changes up to this point */ + if (found) + atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC), + &ctrl->pending_events); + + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status); + if ((lnk_status & PCI_EXP_LNKSTA_LT) || + !(lnk_status & PCI_EXP_LNKSTA_NLW)) { + ctrl_info(ctrl, "Slot(%s): Cannot train link: status %#06x\n", + slot_name(ctrl), lnk_status); + return -1; + } + + pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status); + + if (!found) { + ctrl_info(ctrl, "Slot(%s): No device found\n", + slot_name(ctrl)); + return -1; + } + + return 0; +} + +static int __pciehp_link_set(struct controller *ctrl, bool enable) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + + pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_LD, + enable ? 0 : PCI_EXP_LNKCTL_LD); + + return 0; +} + +static int pciehp_link_enable(struct controller *ctrl) +{ + return __pciehp_link_set(ctrl, true); +} + +int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot, + u8 *status) +{ + struct controller *ctrl = to_ctrl(hotplug_slot); + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_ctrl; + + pci_config_pm_runtime_get(pdev); + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + pci_config_pm_runtime_put(pdev); + *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6; + return 0; +} + +int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status) +{ + struct controller *ctrl = to_ctrl(hotplug_slot); + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_ctrl; + + pci_config_pm_runtime_get(pdev); + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + pci_config_pm_runtime_put(pdev); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl); + + switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) { + case PCI_EXP_SLTCTL_ATTN_IND_ON: + *status = 1; /* On */ + break; + case PCI_EXP_SLTCTL_ATTN_IND_BLINK: + *status = 2; /* Blink */ + break; + case PCI_EXP_SLTCTL_ATTN_IND_OFF: + *status = 0; /* Off */ + break; + default: + *status = 0xFF; + break; + } + + return 0; +} + +void pciehp_get_power_status(struct controller *ctrl, u8 *status) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_ctrl; + + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl); + + switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) { + case PCI_EXP_SLTCTL_PWR_ON: + *status = 1; /* On */ + break; + case PCI_EXP_SLTCTL_PWR_OFF: + *status = 0; /* Off */ + break; + default: + *status = 0xFF; + break; + } +} + +void pciehp_get_latch_status(struct controller *ctrl, u8 *status) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_status; + + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + *status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS); +} + +/** + * pciehp_card_present() - Is the card present + * @ctrl: PCIe hotplug controller + * + * Function checks whether the card is currently present in the slot and + * in that case returns true. Note it is possible that the card is + * removed immediately after the check so the caller may need to take + * this into account. + * + * It the hotplug controller itself is not available anymore returns + * %-ENODEV. + */ +int pciehp_card_present(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_status; + int ret; + + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(slot_status)) + return -ENODEV; + + return !!(slot_status & PCI_EXP_SLTSTA_PDS); +} + +/** + * pciehp_card_present_or_link_active() - whether given slot is occupied + * @ctrl: PCIe hotplug controller + * + * Unlike pciehp_card_present(), which determines presence solely from the + * Presence Detect State bit, this helper also returns true if the Link Active + * bit is set. This is a concession to broken hotplug ports which hardwire + * Presence Detect State to zero, such as Wilocity's [1ae9:0200]. + * + * Returns: %1 if the slot is occupied and %0 if it is not. If the hotplug + * port is not present anymore returns %-ENODEV. + */ +int pciehp_card_present_or_link_active(struct controller *ctrl) +{ + int ret; + + ret = pciehp_card_present(ctrl); + if (ret) + return ret; + + return pciehp_check_link_active(ctrl); +} + +int pciehp_query_power_fault(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_status; + + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + return !!(slot_status & PCI_EXP_SLTSTA_PFD); +} + +int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot, + u8 status) +{ + struct controller *ctrl = to_ctrl(hotplug_slot); + struct pci_dev *pdev = ctrl_dev(ctrl); + + pci_config_pm_runtime_get(pdev); + pcie_write_cmd_nowait(ctrl, status << 6, + PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC); + pci_config_pm_runtime_put(pdev); + return 0; +} + +/** + * pciehp_set_indicators() - set attention indicator, power indicator, or both + * @ctrl: PCIe hotplug controller + * @pwr: one of: + * PCI_EXP_SLTCTL_PWR_IND_ON + * PCI_EXP_SLTCTL_PWR_IND_BLINK + * PCI_EXP_SLTCTL_PWR_IND_OFF + * @attn: one of: + * PCI_EXP_SLTCTL_ATTN_IND_ON + * PCI_EXP_SLTCTL_ATTN_IND_BLINK + * PCI_EXP_SLTCTL_ATTN_IND_OFF + * + * Either @pwr or @attn can also be INDICATOR_NOOP to leave that indicator + * unchanged. + */ +void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn) +{ + u16 cmd = 0, mask = 0; + + if (PWR_LED(ctrl) && pwr != INDICATOR_NOOP) { + cmd |= (pwr & PCI_EXP_SLTCTL_PIC); + mask |= PCI_EXP_SLTCTL_PIC; + } + + if (ATTN_LED(ctrl) && attn != INDICATOR_NOOP) { + cmd |= (attn & PCI_EXP_SLTCTL_AIC); + mask |= PCI_EXP_SLTCTL_AIC; + } + + if (cmd) { + pcie_write_cmd_nowait(ctrl, cmd, mask); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd); + } +} + +int pciehp_power_on_slot(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 slot_status; + int retval; + + /* Clear power-fault bit from previous power failures */ + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (slot_status & PCI_EXP_SLTSTA_PFD) + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_PFD); + ctrl->power_fault_detected = 0; + + pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, + PCI_EXP_SLTCTL_PWR_ON); + + retval = pciehp_link_enable(ctrl); + if (retval) + ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__); + + return retval; +} + +void pciehp_power_off_slot(struct controller *ctrl) +{ + pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, + PCI_EXP_SLTCTL_PWR_OFF); +} + +static void pciehp_ignore_dpc_link_change(struct controller *ctrl, + struct pci_dev *pdev, int irq) +{ + /* + * Ignore link changes which occurred while waiting for DPC recovery. + * Could be several if DPC triggered multiple times consecutively. + */ + synchronize_hardirq(irq); + atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events); + if (pciehp_poll_mode) + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n", + slot_name(ctrl)); + + /* + * If the link is unexpectedly down after successful recovery, + * the corresponding link change may have been ignored above. + * Synthesize it to ensure that it is acted on. + */ + down_read_nested(&ctrl->reset_lock, ctrl->depth); + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + up_read(&ctrl->reset_lock); +} + +static irqreturn_t pciehp_isr(int irq, void *dev_id) +{ + struct controller *ctrl = (struct controller *)dev_id; + struct pci_dev *pdev = ctrl_dev(ctrl); + struct device *parent = pdev->dev.parent; + u16 status, events = 0; + + /* + * Interrupts only occur in D3hot or shallower and only if enabled + * in the Slot Control register (PCIe r4.0, sec 6.7.3.4). + */ + if (pdev->current_state == PCI_D3cold || + (!(ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE) && !pciehp_poll_mode)) + return IRQ_NONE; + + /* + * Keep the port accessible by holding a runtime PM ref on its parent. + * Defer resume of the parent to the IRQ thread if it's suspended. + * Mask the interrupt until then. + */ + if (parent) { + pm_runtime_get_noresume(parent); + if (!pm_runtime_active(parent)) { + pm_runtime_put(parent); + disable_irq_nosync(irq); + atomic_or(RERUN_ISR, &ctrl->pending_events); + return IRQ_WAKE_THREAD; + } + } + +read_status: + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status); + if (PCI_POSSIBLE_ERROR(status)) { + ctrl_info(ctrl, "%s: no response from device\n", __func__); + if (parent) + pm_runtime_put(parent); + return IRQ_NONE; + } + + /* + * Slot Status contains plain status bits as well as event + * notification bits; right now we only want the event bits. + */ + status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | + PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC | + PCI_EXP_SLTSTA_DLLSC; + + /* + * If we've already reported a power fault, don't report it again + * until we've done something to handle it. + */ + if (ctrl->power_fault_detected) + status &= ~PCI_EXP_SLTSTA_PFD; + else if (status & PCI_EXP_SLTSTA_PFD) + ctrl->power_fault_detected = true; + + events |= status; + if (!events) { + if (parent) + pm_runtime_put(parent); + return IRQ_NONE; + } + + if (status) { + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status); + + /* + * In MSI mode, all event bits must be zero before the port + * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4). + * So re-read the Slot Status register in case a bit was set + * between read and write. + */ + if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode) + goto read_status; + } + + ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events); + if (parent) + pm_runtime_put(parent); + + /* + * Command Completed notifications are not deferred to the + * IRQ thread because it may be waiting for their arrival. + */ + if (events & PCI_EXP_SLTSTA_CC) { + ctrl->cmd_busy = 0; + smp_mb(); + wake_up(&ctrl->queue); + + if (events == PCI_EXP_SLTSTA_CC) + return IRQ_HANDLED; + + events &= ~PCI_EXP_SLTSTA_CC; + } + + if (pdev->ignore_hotplug) { + ctrl_dbg(ctrl, "ignoring hotplug event %#06x\n", events); + return IRQ_HANDLED; + } + + /* Save pending events for consumption by IRQ thread. */ + atomic_or(events, &ctrl->pending_events); + return IRQ_WAKE_THREAD; +} + +static irqreturn_t pciehp_ist(int irq, void *dev_id) +{ + struct controller *ctrl = (struct controller *)dev_id; + struct pci_dev *pdev = ctrl_dev(ctrl); + irqreturn_t ret; + u32 events; + + ctrl->ist_running = true; + pci_config_pm_runtime_get(pdev); + + /* rerun pciehp_isr() if the port was inaccessible on interrupt */ + if (atomic_fetch_and(~RERUN_ISR, &ctrl->pending_events) & RERUN_ISR) { + ret = pciehp_isr(irq, dev_id); + enable_irq(irq); + if (ret != IRQ_WAKE_THREAD) + goto out; + } + + synchronize_hardirq(irq); + events = atomic_xchg(&ctrl->pending_events, 0); + if (!events) { + ret = IRQ_NONE; + goto out; + } + + /* Check Attention Button Pressed */ + if (events & PCI_EXP_SLTSTA_ABP) { + ctrl_info(ctrl, "Slot(%s): Attention button pressed\n", + slot_name(ctrl)); + pciehp_handle_button_press(ctrl); + } + + /* Check Power Fault Detected */ + if (events & PCI_EXP_SLTSTA_PFD) { + ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl)); + pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF, + PCI_EXP_SLTCTL_ATTN_IND_ON); + } + + /* + * Ignore Link Down/Up events caused by Downstream Port Containment + * if recovery from the error succeeded. + */ + if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) && + ctrl->state == ON_STATE) { + events &= ~PCI_EXP_SLTSTA_DLLSC; + pciehp_ignore_dpc_link_change(ctrl, pdev, irq); + } + + /* + * Disable requests have higher priority than Presence Detect Changed + * or Data Link Layer State Changed events. + */ + down_read_nested(&ctrl->reset_lock, ctrl->depth); + if (events & DISABLE_SLOT) + pciehp_handle_disable_request(ctrl); + else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) + pciehp_handle_presence_or_link_change(ctrl, events); + up_read(&ctrl->reset_lock); + + ret = IRQ_HANDLED; +out: + pci_config_pm_runtime_put(pdev); + ctrl->ist_running = false; + wake_up(&ctrl->requester); + return ret; +} + +static int pciehp_poll(void *data) +{ + struct controller *ctrl = data; + + schedule_timeout_idle(10 * HZ); /* start with 10 sec delay */ + + while (!kthread_should_stop()) { + /* poll for interrupt events or user requests */ + while (pciehp_isr(IRQ_NOTCONNECTED, ctrl) == IRQ_WAKE_THREAD || + atomic_read(&ctrl->pending_events)) + pciehp_ist(IRQ_NOTCONNECTED, ctrl); + + if (pciehp_poll_time <= 0 || pciehp_poll_time > 60) + pciehp_poll_time = 2; /* clamp to sane value */ + + schedule_timeout_idle(pciehp_poll_time * HZ); + } + + return 0; +} + +static void pcie_enable_notification(struct controller *ctrl) +{ + u16 cmd, mask; + + /* + * TBD: Power fault detected software notification support. + * + * Power fault detected software notification is not enabled + * now, because it caused power fault detected interrupt storm + * on some machines. On those machines, power fault detected + * bit in the slot status register was set again immediately + * when it is cleared in the interrupt service routine, and + * next power fault detected interrupt was notified again. + */ + + /* + * Always enable link events: thus link-up and link-down shall + * always be treated as hotplug and unplug respectively. Enable + * presence detect only if Attention Button is not present. + */ + cmd = PCI_EXP_SLTCTL_DLLSCE; + if (ATTN_BUTTN(ctrl)) + cmd |= PCI_EXP_SLTCTL_ABPE; + else + cmd |= PCI_EXP_SLTCTL_PDCE; + if (!pciehp_poll_mode) + cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE; + + mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE | + PCI_EXP_SLTCTL_PFDE | + PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE | + PCI_EXP_SLTCTL_DLLSCE); + + pcie_write_cmd_nowait(ctrl, cmd, mask); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd); +} + +static void pcie_disable_notification(struct controller *ctrl) +{ + u16 mask; + + mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE | + PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE | + PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE | + PCI_EXP_SLTCTL_DLLSCE); + pcie_write_cmd(ctrl, 0, mask); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0); +} + +void pcie_clear_hotplug_events(struct controller *ctrl) +{ + pcie_capability_write_word(ctrl_dev(ctrl), PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC); +} + +void pcie_enable_interrupt(struct controller *ctrl) +{ + u16 mask; + + mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE; + pcie_write_cmd(ctrl, mask, mask); +} + +void pcie_disable_interrupt(struct controller *ctrl) +{ + u16 mask; + + /* + * Mask hot-plug interrupt to prevent it triggering immediately + * when the link goes inactive (we still get PME when any of the + * enabled events is detected). Same goes with Link Layer State + * changed event which generates PME immediately when the link goes + * inactive so mask it as well. + */ + mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE; + pcie_write_cmd(ctrl, 0, mask); +} + +/** + * pciehp_slot_reset() - ignore link event caused by error-induced hot reset + * @dev: PCI Express port service device + * + * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset + * further up in the hierarchy to recover from an error. The reset was + * propagated down to this hotplug port. Ignore the resulting link flap. + * If the link failed to retrain successfully, synthesize the ignored event. + * Surprise removal during reset is detected through Presence Detect Changed. + */ +int pciehp_slot_reset(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + + if (ctrl->state != ON_STATE) + return 0; + + pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + + return 0; +} + +/* + * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary + * bus reset of the bridge, but at the same time we want to ensure that it is + * not seen as a hot-unplug, followed by the hot-plug of the device. Thus, + * disable link state notification and presence detection change notification + * momentarily, if we see that they could interfere. Also, clear any spurious + * events after. + */ +int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe) +{ + struct controller *ctrl = to_ctrl(hotplug_slot); + struct pci_dev *pdev = ctrl_dev(ctrl); + u16 stat_mask = 0, ctrl_mask = 0; + int rc; + + if (probe) + return 0; + + down_write_nested(&ctrl->reset_lock, ctrl->depth); + + if (!ATTN_BUTTN(ctrl)) { + ctrl_mask |= PCI_EXP_SLTCTL_PDCE; + stat_mask |= PCI_EXP_SLTSTA_PDC; + } + ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE; + stat_mask |= PCI_EXP_SLTSTA_DLLSC; + + pcie_write_cmd(ctrl, 0, ctrl_mask); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0); + + rc = pci_bridge_secondary_bus_reset(ctrl->pcie->port); + + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask); + pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask); + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__, + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask); + + up_write(&ctrl->reset_lock); + return rc; +} + +int pcie_init_notification(struct controller *ctrl) +{ + if (pciehp_request_irq(ctrl)) + return -1; + pcie_enable_notification(ctrl); + ctrl->notification_enabled = 1; + return 0; +} + +void pcie_shutdown_notification(struct controller *ctrl) +{ + if (ctrl->notification_enabled) { + pcie_disable_notification(ctrl); + pciehp_free_irq(ctrl); + ctrl->notification_enabled = 0; + } +} + +static inline void dbg_ctrl(struct controller *ctrl) +{ + struct pci_dev *pdev = ctrl->pcie->port; + u16 reg16; + + ctrl_dbg(ctrl, "Slot Capabilities : 0x%08x\n", ctrl->slot_cap); + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, ®16); + ctrl_dbg(ctrl, "Slot Status : 0x%04x\n", reg16); + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, ®16); + ctrl_dbg(ctrl, "Slot Control : 0x%04x\n", reg16); +} + +#define FLAG(x, y) (((x) & (y)) ? '+' : '-') + +static inline int pcie_hotplug_depth(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->bus; + int depth = 0; + + while (bus->parent) { + bus = bus->parent; + if (bus->self && bus->self->is_hotplug_bridge) + depth++; + } + + return depth; +} + +struct controller *pcie_init(struct pcie_device *dev) +{ + struct controller *ctrl; + u32 slot_cap, slot_cap2, link_cap; + u8 poweron; + struct pci_dev *pdev = dev->port; + struct pci_bus *subordinate = pdev->subordinate; + + ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return NULL; + + ctrl->pcie = dev; + ctrl->depth = pcie_hotplug_depth(dev->port); + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); + + if (pdev->hotplug_user_indicators) + slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP); + + /* + * We assume no Thunderbolt controllers support Command Complete events, + * but some controllers falsely claim they do. + */ + if (pdev->is_thunderbolt) + slot_cap |= PCI_EXP_SLTCAP_NCCS; + + ctrl->slot_cap = slot_cap; + mutex_init(&ctrl->ctrl_lock); + mutex_init(&ctrl->state_lock); + init_rwsem(&ctrl->reset_lock); + init_waitqueue_head(&ctrl->requester); + init_waitqueue_head(&ctrl->queue); + INIT_DELAYED_WORK(&ctrl->button_work, pciehp_queue_pushbutton_work); + dbg_ctrl(ctrl); + + down_read(&pci_bus_sem); + ctrl->state = list_empty(&subordinate->devices) ? OFF_STATE : ON_STATE; + up_read(&pci_bus_sem); + + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP2, &slot_cap2); + if (slot_cap2 & PCI_EXP_SLTCAP2_IBPD) { + pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_IBPD_DISABLE, + PCI_EXP_SLTCTL_IBPD_DISABLE); + ctrl->inband_presence_disabled = 1; + } + + if (dmi_first_match(inband_presence_disabled_dmi_table)) + ctrl->inband_presence_disabled = 1; + + /* Check if Data Link Layer Link Active Reporting is implemented */ + pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap); + + /* Clear all remaining event bits in Slot Status register. */ + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | + PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC | + PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC); + + ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c IbPresDis%c LLActRep%c%s\n", + (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19, + FLAG(slot_cap, PCI_EXP_SLTCAP_ABP), + FLAG(slot_cap, PCI_EXP_SLTCAP_PCP), + FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP), + FLAG(slot_cap, PCI_EXP_SLTCAP_AIP), + FLAG(slot_cap, PCI_EXP_SLTCAP_PIP), + FLAG(slot_cap, PCI_EXP_SLTCAP_HPC), + FLAG(slot_cap, PCI_EXP_SLTCAP_HPS), + FLAG(slot_cap, PCI_EXP_SLTCAP_EIP), + FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS), + FLAG(slot_cap2, PCI_EXP_SLTCAP2_IBPD), + FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC), + pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : ""); + + /* + * If empty slot's power status is on, turn power off. The IRQ isn't + * requested yet, so avoid triggering a notification with this command. + */ + if (POWER_CTRL(ctrl)) { + pciehp_get_power_status(ctrl, &poweron); + if (!pciehp_card_present_or_link_active(ctrl) && poweron) { + pcie_disable_notification(ctrl); + pciehp_power_off_slot(ctrl); + } + } + + return ctrl; +} + +void pciehp_release_ctrl(struct controller *ctrl) +{ + cancel_delayed_work_sync(&ctrl->button_work); + kfree(ctrl); +} + +static void quirk_cmd_compl(struct pci_dev *pdev) +{ + u32 slot_cap; + + if (pci_is_pcie(pdev)) { + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); + if (slot_cap & PCI_EXP_SLTCAP_HPC && + !(slot_cap & PCI_EXP_SLTCAP_NCCS)) + pdev->broken_cmd_compl = 1; + } +} +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x010e, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_HXT, 0x0401, + PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl); |